Methods and apparatus for global optimization of vertical trajectory for an air route

ABSTRACT

A method for calculating vertical trajectory values is provided. The method obtains aircraft performance data for a particular aircraft and atmospheric condition data associated with an air route; calculates a cost-efficient vertical trajectory for the air route, based on the aircraft performance data and the atmospheric condition data, wherein the cost-efficient vertical trajectory comprises a plurality of altitude values for minimizing cost for the particular aircraft during travel of the air route; obtains an altitude consistency threshold; and adjusts the cost-efficient vertical trajectory using the altitude consistency parameter, to create an optimized vertical trajectory for the aircraft route.

TECHNICAL FIELD

Embodiments of the subject matter described herein relate generally tocalculating vertical trajectory for a route flown by an aircraft. Moreparticularly, embodiments of the subject matter relate to determining apractical and cost-efficient vertical trajectory applicable to a route.

BACKGROUND

A vertical trajectory may be defined as a vertical profile of flight. Avertical trajectory of an aircraft, for a particular air route, isgenerally created by a flight management system (FMS) onboard anaircraft. Passenger air travel and air transport of goods are becomingprogressively more costly, due to the rising cost of fuel and otherfactors. The cost of a particular flight (e.g. fuel consumption, flighttime) depends on altitude, weight, aerodynamic performance of aircraft,speed of aircraft and environmental conditions (wind, temperature).

Accordingly, it is desirable to determine practically implementedmethods for reducing the cost of a particular flight. Furthermore, otherdesirable features and characteristics will become apparent from thesubsequent detailed description and the appended claims, taken inconjunction with the accompanying drawings and the foregoing technicalfield and background.

BRIEF SUMMARY

Some embodiments of the present disclosure provide a method forcalculating vertical trajectory values. The method obtains aircraftperformance data for a particular aircraft and atmospheric conditiondata associated with an air route; calculates a cost-efficient verticaltrajectory for the air route, based on the aircraft performance data andthe atmospheric condition data, wherein the cost-efficient verticaltrajectory comprises a plurality of altitude values for minimizing costfor the particular aircraft during travel of the air route, obtains analtitude consistency threshold; and adjusts the cost-efficient verticaltrajectory using the altitude consistency parameter, to create anoptimized vertical trajectory for the aircraft route.

Some embodiments provide a system for calculating vertical trajectoryvalues. The system includes: a system memory element; a communicationdevice, configured to receive atmospheric condition data associated withan air route; and at least one processor communicatively coupled to thesystem memory element and the communication device, the at least oneprocessor configured to: calculate a cost-efficient vertical trajectoryfor the air route, based on the aircraft performance data and theatmospheric condition data, wherein the cost-efficient verticaltrajectory comprises a plurality of altitude values for minimizing costfor the particular aircraft during travel of the air route; and adjustthe cost-efficient vertical trajectory using an altitude consistencythreshold, to generate an optimized vertical trajectory for the aircraftroute.

Some embodiments provide a non-transitory, computer-readable mediumcontaining instructions thereon, which, when executed by a processor,perform a method. The method identifies distance points throughout anair route; calculates a cost-efficient altitude for each of the distancepoints to determine a plurality of cost-efficient altitudes, wherein theplurality of cost-efficient altitudes is applicable to a particularaircraft traveling the air route; determines whether each of theplurality of cost-efficient altitudes complies with an altitudeconsistency threshold; and when one of the plurality of cost-efficientaltitudes does not comply with the altitude consistency threshold,shifts the one of the plurality of cost-efficient altitudes to complywith the altitude consistency threshold.

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the detaileddescription. This summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the subject matter may be derived byreferring to the detailed description and claims when considered inconjunction with the following figures, wherein like reference numbersrefer to similar elements throughout the figures.

FIG. 1 is a diagram of a vertical trajectory optimization system, inaccordance with the disclosed embodiments;

FIG. 2 is a functional block diagram of a computing device suitable foruse in a vertical trajectory optimization system, in accordance with thedisclosed embodiments;

FIG. 3 is a graph illustrating potential altitude values for an airroute, in accordance with the disclosed embodiments;

FIG. 4 is a graph that includes a plot for a cost-efficient verticaltrajectory and an optimized cost-efficient vertical trajectory, inaccordance with the disclosed embodiments;

FIG. 5 is a three-dimensional (3D) graph illustrating potential altitudevalues for an air route, and an optimized cost-efficient verticaltrajectory, in accordance with the disclosed embodiments;

FIG. 6 is a flow chart that illustrates an embodiment of a process forcalculating vertical trajectory values;

FIG. 7 is a flow chart that illustrates an embodiment of a process forcalculating a cost-efficient vertical trajectory;

FIG. 8 is a flow chart that illustrates an embodiment of a process forgenerating an optimized vertical trajectory for an air route; and

FIG. 9 is a flow chart that illustrates an embodiment of a process forcalculating an optimized cost-efficient vertical trajectory on apoint-by-point basis.

DETAILED DESCRIPTION

The following detailed description is merely illustrative in nature andis not intended to limit the embodiments of the subject matter or theapplication and uses of such embodiments. As used herein, the word“exemplary” means “serving as an example, instance, or illustration.”Any implementation described herein as exemplary is not necessarily tobe constructed as preferred or advantageous over other implementations.Furthermore, there is no intention to be bound by any expressed orimplied theory presented in the preceding technical field, background,brief summary or the following detailed description.

The present disclosure presents methods and apparatus for calculatingand providing an optimized vertical trajectory for an air route. An airroute may be defined as a flight path form a first defined location to asecond defined location, and a vertical trajectory for an air routeincludes one or more altitude values at which an aircraft is instructedto fly while traveling the air route. In the context of the presentdisclosure, the vertical trajectory is “optimized” by determiningcost-efficient, yet practically-implemented, altitude values for theparticular air route. Exemplary embodiments of the present disclosurefirst calculate a part of vertical trajectory which consumes a low levelof fuel, based on an aircraft data model and atmospheric conditions forthe air route, and then optimize the calculated vertical trajectory byimplementing conditions associated with practical flying principles.Examples of such conditions may include implementing an altitudeconsistency threshold (e.g., maintaining an altitude level for aparticular period of time, a particular distance value, transition toanother airspace sector, transition to another air navigation serviceprovider (ANSP), or the like).

Turning now to the figures, FIG. 1 is a diagram of an exemplaryembodiment of a vertical trajectory optimization system 100. As shown,vertical trajectory optimization system 100 generally includes, withoutlimitation, a computing device 102 onboard an aircraft 104 incommunication with at least one server 106. The computing device 102 maybe implemented using any device which includes at least one processor,some form of computing memory, and input/output (I/O) for transmittingand receiving aircraft performance data onboard the aircraft 104 andatmospheric condition data from the at least one server 106. Thecomputing device 102 may be implemented using a computer systemintegrated into the aircraft or a personal electronic device. In certainembodiments, the computing device 102 may include the capability ofdownloading, storing, and executing software applications (i.e., “apps”)which include the vertical trajectory optimization functionalitydescribed herein. Exemplary embodiments of a computing device 102 mayinclude, without limitation; a laptop computer, a tablet computer, ahandheld personal digital assistant, a smartphone, a smartwatch, orother personal electronic device with the capability of communicatingwith aircraft onboard systems and the at least one server 106.

The computing device 102 may transmit data to, and receive data from,the at least one server 106 via a data communication network 108. Thedata communication network 108 may be any digital or othercommunications network capable of transmitting messages or data betweendevices, systems, or components. In certain embodiments, the datacommunication network 108 includes a packet switched network thatfacilitates packet-based data communication, addressing, and datarouting. The packet switched network could be, for example, a wide areanetwork, the Internet, or the like. In various embodiments, the datacommunication network 108 includes any number of public or private dataconnections, links or network connections supporting any number ofcommunications protocols. The data communication network 108 may includethe Internet, for example, or any other network based upon TCP/IP orother conventional protocols. In various embodiments, the datacommunication network 108 could also incorporate a wireless and/or wiredtelephone network, such as a cellular communications network forcommunicating with mobile phones, personal digital assistants, and/orthe like. The data communication network 108 may also incorporate anysort of wireless or wired local and/or personal area networks, such asone or more IEEE 802.3, IEEE 802.16, and/or IEEE 802.11 networks, and/ornetworks that implement a short range (e.g., Bluetooth) protocol. Forthe sake of brevity, conventional techniques related to datatransmission, signaling, network control, and other functional aspectsof the systems (and the individual operating components of the systems)may not be described in detail herein.

The at least one server 106 may include any number of applicationservers, and each server may be implemented using any suitable computer.In some embodiments, the at least one server 106 includes one or morededicated computers. In some embodiments, the at least one server 106includes one or more computers carrying out other functionality inaddition to server operations. In exemplary embodiments, the at leastone server 106 stores and provides atmospheric data, which may include,without limitation: temperature, wind speed, wind direction, windmagnitude, turbulence, lightning, and/or other significant atmosphericphenomena which should be avoided by the aircraft 104 in flight.

Prior to flight, or during flight, the computing device 102 usesatmospheric data or weather forecast and performance data associatedwith the particular aircraft to calculate an optimized andcost-efficient vertical trajectory for an entire air route. In certainembodiments, the computing device 102 first determines the mostcost-efficient vertical trajectory for the air route, and then optimizesthe cost-efficient vertical trajectory by “smoothing” the verticaltrajectory altitude values. The operationally optimized, or in otherwords, “smoothed” vertical trajectory altitude values represent a morepractically implemented vertical trajectory for the air route, whichalso maintains a lower level of fuel consumption for the aircraft 104than would be used under normal conditions (e.g., using a flightmanagement system (FMS) generated vertical trajectory which does notconsider evolution of atmospheric condition along whole trajectory atonce). It should be appreciated that, in other embodiments, thecomputing device 102 may determine the most cost-efficient verticaltrajectory and the optimized cost-efficient vertical trajectory duringone combined process. For example, as the computing device 102calculates each value for the cost-efficient vertical trajectory, thecomputing device 102 concurrently rejects transitions which do not meetrequired criteria for the optimized cost-efficient vertical trajectory.

In the particular embodiment shown in FIG. 1, the computing device 102is located onboard the aircraft 104 and performs the vertical trajectoryoptimization techniques at this location. However, it should beappreciated that other embodiments of the vertical trajectoryoptimization system 100 may instead position the computing device 102 ata ground location. In this example, the computing device 102 may receiveinput and/or requests from the aircraft 104, perform the verticaltrajectory optimization functionality, and then transmit optimizedvertical trajectory data to the aircraft 104 for use.

FIG. 2 is a functional block diagram of a computing device 200 suitablefor use in a vertical trajectory optimization system, in accordance withthe disclosed embodiments. It should be noted that the computing device200 can be implemented with the computing device 102 depicted in FIG. 1.In this regard, the computing device 200 shows certain elements andcomponents of the computing device 102 in more detail.

The computing device 200 generally includes, without limitation: atleast one processor 202; system memory 204; a user interface 206; acommunication device 208; a vertical trajectory calculation module 210;and a presentation module 212. These elements and features of thecomputing device 200 may be operatively associated with one another,coupled to one another, or otherwise configured to cooperate with oneanother as needed to support the desired functionality—in particular,vertical trajectory optimization, as described herein. For ease ofillustration and clarity, the various physical, electrical, and logicalcouplings and interconnections for these elements and features are notdepicted in FIG. 2. Moreover, it should be appreciated that embodimentsof the computing device 200 will include other elements, modules, andfeatures that cooperate to support the desired functionality. Forsimplicity, FIG. 2 only depicts certain elements that relate to thevertical trajectory optimization techniques described in more detailbelow.

The at least one processor 202 may be implemented or performed with oneor more general purpose processors, a content addressable memory, adigital signal processor, an application specific integrated circuit, afield programmable gate array, any suitable programmable logic device,discrete gate or transistor logic, discrete hardware components, or anycombination designed to perform the functions described here. Inparticular, the at least one processor 202 may be realized as one ormore microprocessors, controllers, microcontrollers, or state machines.Moreover, the at least one processor 202 may be implemented as acombination of computing devices, e.g., a combination of digital signalprocessors and microprocessors, a plurality of microprocessors, one ormore microprocessors in conjunction with a digital signal processorcore, or any other such configuration.

The at least one processor 202 communicates with system memory 204. Thesystem memory 204 may be used to store a calculated air route data,vertical trajectory data for a particular air route, altitudeconsistency threshold data, aircraft performance data, atmospheric dataassociated with particular air routes, or the like.

The system memory 204 may be realized using any number of devices,components, or modules, as appropriate to the embodiment. In practice,the system memory 204 could be realized as RAM memory, flash memory,EPROM memory, EEPROM memory, registers, a hard disk, a removable disk,or any other form of storage medium known in the art. In certainembodiments, the system memory 204 includes a hard disk, which may alsobe used to support functions of the at least one processor 202. Thesystem memory 204 can be coupled to the at least one processor 202 suchthat the at least one processor 202 can read information from, and writeinformation to, the system memory 204. In the alternative, the systemmemory 204 may be integral to the at least one processor 202. As anexample, the at least one processor 202 and the system memory 204 mayreside in a suitably designated application-specific integrated circuit(ASIC).

The user interface 206 may include or cooperate with various features toallow a user to interact with the computing device 200. Accordingly, theuser interface 206 may include various human-to-machine interfaces,e.g., a keypad, keys, a keyboard, buttons, switches, knobs, a touchpad,a joystick, a pointing device, a virtual writing tablet, a touch screen,a microphone, or any device, component, or function that enables theuser to select options, input information, or otherwise control theoperation of the computing device 200. For example, the user interface206 could be manipulated by an operator to make menu selections forpurposes of viewing available SOP monitoring alerts and notificationsindicating SOP compliance or non-compliance of various aircraft onboardsystems.

In certain embodiments, the user interface 206 may include or cooperatewith various features to allow a user to interact with the computingdevice 200 via graphical elements rendered on a display element.Accordingly, the user interface 206 may initiate the creation,maintenance, and presentation of a graphical user interface (GUI). Incertain embodiments, the display element implements touch-sensitivetechnology for purposes of interacting with the GUI. Thus, a user canmanipulate the GUI by moving a cursor symbol rendered on the displayelement, or by physically interacting with the display element itselffor recognition and interpretation, via the user interface 206.

The communication device 208 is suitably configured to communicate databetween the computing device 200 and one or more remote servers (see,for example, FIG. 1). As described in more detail below, data receivedby the communication device 208 may include, without limitation,atmospheric data associated with a particular air route and aircraftperformance data associated with the aircraft. Data provided by thecommunication device 208 may include requests for aircraft performancedata, air route data, atmospheric data associated with a particular airroute, or the like.

The communication device 208 may transmit and receive communicationsover a wireless local area network (WLAN), the Internet, a satelliteuplink/downlink, a cellular network, a broadband network, a wide areanetwork, or any standard method of aircraft communication. In certainembodiments, the communication device 208 is implemented as an onboardaircraft communication or telematics system. In embodiments wherein thecommunication device 208 is a telematics module, an internal transceivermay be capable of providing bi-directional mobile phone voice and datacommunication, implemented as Code Division Multiple Access (CDMA). Insome embodiments, other 3G, 4G, and/or 5G technologies may be used toimplement the communication device 208, including without limitationUniversal Mobile Telecommunications System (UMTS) wideband CDMA(W-CDMA), Enhanced Data Rates for GSM Evolution (EDGE), Evolved EDGE,High Speed Packet Access (HSPA), CDMA2000, Evolved High Speed PacketAccess (HSPA+), Long Term Evolution (LTE) and/or Long TermEvolution-Advanced (LTE-A).

The vertical trajectory calculation module 210 is configured to analyzeair route data, atmospheric data associated with the air route, andaircraft performance data (obtained via the communication device 208) tocalculate cost-efficient altitude values for each distance pointthroughout the air route. The vertical trajectory calculation module 210is further configured to optimize the cost-efficient altitude values inorder to produce an optimized vertical trajectory for the length of theair route.

The presentation module 212 is configured to operate cooperatively withthe user interface 206 to provide a visual representation of anoptimized vertical trajectory for an air route. In certain embodiments,the presentation module 212 displays a graphical user interface (GUI)which may include user-selectable options, menus, icons, and/or othergraphical elements appropriate to request optimized vertical trajectorydata (as determined by the vertical trajectory calculation module 210).

In practice, the vertical trajectory calculation module 210 and/or thepresentation module 212 may be implemented with (or cooperate with) theat least one processor 202 to perform at least some of the functions andoperations described in more detail herein. In this regard, the verticaltrajectory calculation module 210 and/or the presentation module 212 maybe realized as suitably written processing logic, application programcode, or the like.

FIG. 3 is a graph 300 illustrating potential altitude values for aparticular air route, in accordance with the disclosed embodiments. Thegraph 300 includes distance values 302 along the x-axis and altitudevalues 304 along the y-axis, and illustrates the relationship betweenpotential altitude values 304 for each distance value 302 for aparticular aircraft traveling the particular air route. It should beappreciated that the depicted distance values and potential altitudevalues for the air route shown in FIG. 3 represent one exemplaryembodiment, and that other air routes may be associated with greater orlesser distance values and/or potential altitude values. Each of thedistance values 302 is associated with a plurality of potential altitudevalues 304. The potential altitude values 304 for one of the distancevalues 302 are shown as a group of dots above each distance value 302.The dots/potential altitudes can be computed by different algorithms. Inthis case, the algorithm selects the potential altitudes below and abovea nominal/the probable average flight profile based on particularaircraft performance.

The vertical trajectory optimization system (described previously withregard to FIGS. 1-2) is configured to: (i) recognize the group of dots(i.e., the potential altitude values 304) for a particular one of thedistance values 302, (ii) compute the cost-efficiency of each of thedots, and (iii) select a particular dot (i.e., altitude value 304) foreach of the distance values 302, based on the cost-efficiency of eachdot. In certain embodiments, a selected dot may represent the mostcost-efficient altitude value available for a particular distance value302. In some embodiments, however, other factors may be considered, andthe selected dot may represent a high level of cost-efficiency (whencompared to other levels of cost-efficiency associated with otheraltitude values 304 for the particular distance value 302), but notnecessarily the highest level of cost-efficiency. Here, no constraintsare taken into consideration, aside from cost-efficiency, to generatesthe most cost-efficient vertical trajectory within operationallimitations of the aircraft. The algorithm evaluates the cost functionof effectively all of the feasible vertical trajectories and selects themost cost-efficient. Collectively, the group of selected, particulardots extends from the beginning point of the air route to the endpointof the air route, and represent a cost-efficient vertical trajectory forthe air route, as shown in FIG. 4.

FIG. 4 is a graph 400 that includes a plot for a cost-efficient verticaltrajectory 402 and an optimized cost-efficient vertical trajectory 404,applicable to a particular air route, a particular aircraft, underparticular atmospheric conditions. The graph 400 includes distancevalues 408 along the x-axis and altitude values 410 along the y-axis,and illustrates the relationship between applicable altitude values 410for each distance value 408 for a particular air route, when calculatedfor the cost-efficient vertical trajectory 402 and the optimizedcost-efficient vertical trajectory 404.

The cost-efficient vertical trajectory 402 is computed as described withregard to FIG. 3. The vertical trajectory optimization system (describedpreviously with regard to FIGS. 1-2) “optimizes” the cost-efficientvertical trajectory 402, at each altitude point, to create the optimizedcost-efficient vertical trajectory 404, which is a morepractically-implemented vertical trajectory, and which also reduces fuelconsumption of the aircraft. Because computation of the cost-efficientvertical trajectory 402 considers fuel economy without regard for otherfactors (such as aviation best practices, flight crew and/or passengercomfort, or the like), the vertical trajectory optimization systemadjusts the cost-efficient altitude values for other factors to producethe optimized cost-efficient vertical trajectory 404.

In certain embodiments, the cost-efficient vertical trajectory 402 isadjusted to ensure that each altitude value is maintained for a timeperiod threshold prior to transition to another altitude value. In someembodiments, the cost-efficient vertical trajectory 402 is adjusted toensure that each altitude value is maintained for a distance valuethreshold prior to transition to another altitude value. This“smoothing” of the cost-efficient vertical trajectory 402 is shown inarea 406, where the optimized cost-efficient vertical trajectory 404maintains a consistent altitude value, while the cost-efficient verticaltrajectory 402 changes altitude several times.

Adjustments may also be made to the cost-efficient vertical trajectory402 to ensure that drastic maneuvers are not recommended in theoptimized cost-efficient vertical trajectory 404. For example, as shownin area 412, the cost-efficient vertical trajectory 402 descends to27,000 ft., and then immediately climbs to 29,000 ft. In certainembodiments, the vertical trajectory optimization system may remove thisdescent and immediate climb to present a more consistent recommendedaltitude, as shown by the optimized cost-efficient vertical trajectory404.

In some embodiments, the cost-efficient vertical trajectory 402 iscalculated and then optimized as a whole. However, in some embodiments,the cost-efficient vertical trajectory 402 is calculated point-by-point,and optimizes each point as it is calculated to produce a single,optimized, cost-efficient vertical trajectory 404.

FIG. 5 is a three-dimensional (3D) graph 500 illustrating potentialaltitude values for an air route, and an optimized cost-efficientvertical trajectory, in accordance with the disclosed embodiments. Asshown, the evaluated 3D graph 500 displays a lateral path 502 which isrepresentative of an optimized cost-efficient vertical trajectory. Here,the 3D graph 500 includes a plurality of dots connected by lines. Eachdot represents a potential location through which the plane can fly, andthe lines represent enabled paths from one dot to another. Together, thedots and lines represent an oriented graph, and an aircraft can fly froma column at certain altitude to n-different altitudes in the nextcolumn. Evaluation of potential altitude values, to determinecost-efficient altitude values and/or optimized cost-efficient altitudevalues, proceeds column by column. Each column includes the potentialaltitude values (i.e., potential points) for aircraft travel, when theaircraft has traveled through a determined previous point in theprevious column. Evaluation of a particular, current point considersthis previous point, which represents an optimized cost-efficientaltitude for the previous column. From any point (i.e., altitude value)through its previous points, it is possible to locate a lateral path tothe beginning of the graph, wherein the lateral path represents theoptimal path, or in other words, the optimized cost-efficient verticaltrajectory. Optimal path can be very “peaky” and might need smoothing.

Determining cost-efficient altitude values and/or optimizedcost-efficient altitude values may be accomplished using one or moretechniques. As a first technique, operational limits may be implementeddirectly in the column-by-column graph evaluation, to produce anoptimized cost-efficient vertical trajectory in a point-by-point manner.As a second technique, a cost-efficient vertical trajectory for the airroute may be calculated first, and then post-processing procedures maybe used to “smooth” or optimize the cost-efficient vertical trajectoryto produce an optimized cost-efficient vertical trajectory for the airroute.

FIG. 6 is a flow chart that illustrates an embodiment of a process 600for calculating vertical trajectory values. The various tasks performedin connection with process 600 may be performed by software, hardware,firmware, or any combination thereof. For illustrative purposes, thefollowing description of process 600 may refer to elements mentionedabove in connection with FIGS. 1-5. In practice, portions of process 600may be performed by different elements of the described system. Itshould be appreciated that process 600 may include any number ofadditional or alternative tasks, the tasks shown in FIG. 6 need not beperformed in the illustrated order, and process 600 may be incorporatedinto a more comprehensive procedure or process having additionalfunctionality not described in detail herein. Moreover, one or more ofthe tasks shown in FIG. 6 could be omitted from an embodiment of theprocess 600 as long as the intended overall functionality remainsintact.

For ease of description and clarity, this example assumes that theprocess 600 begins by obtaining aircraft performance data for aparticular aircraft and atmospheric condition data associated with anair route (step 602). Aircraft performance data refers toaircraft-specific modeling and operational parameters, which mayinclude, without limitation: engine data, angle of attack, fuelconsumption for a given altitude, thrust, data provided by the aircraftmanufacturer, and the like. Atmospheric data refers to weatherconditions at a particular distance location and altitude for aparticular air route, and may include, without limitation: airtemperature, wind speed, wind direction, air pressure, lightning,turbulence, and/or other atmospheric conditions that should be avoidedby an in-flight aircraft.

Next, the process 600 calculates a cost-efficient vertical trajectoryfor the air route, based on the aircraft performance data and theatmospheric condition data (step 604). One suitable methodology forcalculating the cost-efficient vertical trajectory is described belowwith reference to FIG. 7. As described previously with regard to FIGS.3-5, the process 600 computes altitude values for a particular aircraftto use, for a particular air route, to reduce fuel consumption of theaircraft. Here, no constraints are taken into consideration, aside fromcost-efficiency, to generate the most cost-efficient vertical trajectorywithin operational limitations of the aircraft. The process 600evaluates the cost function of effectively all of the feasible verticaltrajectories and selects the most cost-efficient.

The process 600 then receives an altitude consistency threshold (step606). The altitude consistency threshold is a time value or distancevalue for which the aircraft is configured to remain at a particularaltitude. For example, an altitude consistency threshold of one hourindicates that, for a particular air route, an aircraft remains at acurrent altitude for a minimum time period of one hour, prior to makinga transition to a different altitude. As another example, an altitudeconsistency threshold of 200 nautical miles (NM) indicates that, whiletraveling the air route, the aircraft remains at a current altitude fora minimum distance of 200 NM, prior to making a transition to adifferent altitude.

In certain embodiments, the altitude consistency threshold is auser-configurable value. In this situation, a user provides the altitudeconsistency threshold via user interface. In some embodiments, however,the altitude consistency threshold may be a preconfigured valueassociated with a particular type of aircraft, a particular air route,and/or particular atmospheric conditions.

Next, the process 600 adjusts the cost-efficient vertical trajectoryusing the altitude consistency threshold, to generate an optimizedvertical trajectory for the air route (step 608). One suitablemethodology for adjusting the cost-efficient vertical trajectory usingthe altitude consistency threshold is described below with reference toFIG. 8. In step 604, the process 600 calculated a cost-efficientvertical trajectory based on the aircraft performance data andatmospheric data associated with the air route. However, the process 600does not consider the practical limitations of flight, which may includeaviation best practices and the comfort and preferences of flight crewmembers and passengers onboard the aircraft. In step 608, the process600 considers these factors by using the altitude consistency thresholdto adjust the calculated, cost-efficient vertical trajectory into an“optimized” vertical trajectory that considers cost-efficiency and alsomaintains each altitude level for at least the altitude consistencythreshold value.

FIG. 7 is a flow chart that illustrates an embodiment of a process 700for calculating a cost-efficient vertical trajectory. It should beappreciated that the process 700 described in FIG. 7 represents oneembodiment of step 604 described above in the discussion of FIG. 6,including additional detail. First, the process 700 identifies distancepoints throughout the air route (step 702). As shown in FIG. 3, an airroute extends from a beginning point to an endpoint, and distance pointsmay identify increments of this air route.

Next, the process 700 calculates a cost-efficient altitude for each ofthe distance points, to determine a plurality of cost-efficientaltitudes (step 704). Each cost-efficient altitude value is calculatedbased on performance data for the particular aircraft and/or type ofaircraft, and atmospheric and weather data for the particular distancepoint of the air route. Altitude values are selected based on expertknowledge. The selection of appropriate altitude values on grid can besubject to adaptation during flight as an output of the process 700 asexecuted in real-time. The process 700 may use certain criteria toidentify each of the altitude values. For example, during cruise phasethe process 700 recognizes that it is counterintuitive to evaluatealtitude values below 50 Nautical Miles (NM) and above 500 NM. Duringclimb and descent, the process 700 recognizes that the altitudes areclosely connected with ability of aircraft climb or descent (+/−5degrees). The process 700 calculates a cost-efficient altitude fromcurrent location or destination incrementally. The process 700 beginswith the first incremental distance from a current altitude ordestination altitude, and calculates the cost of transitions to allavailable altitudes. As the aircraft moves forward during flight of anair route, the aircraft reaches the next distance point in sequence, andall of the possible transitions including operational limitations (i.e.fulfillment of distance threshold, condition against sharp transition)are calculated again, but only the most cost-efficient operationallyfeasible transitions to the altitudes are stored. The process 700repeats until the final destination or current position is reached.

The process 700 then generates a continuous vertical trajectory usingthe plurality of cost-efficient altitudes (step 706). The continuousvertical trajectory indicates a vertical flight path for the aircraft tofollow while traveling the air route, and extends from the beginningpoint of the air route to the endpoint of the air route.

FIG. 8 is a flow chart that illustrates an embodiment of a process 700for generating an optimized vertical trajectory for an air route. Itshould be appreciated that the process 800 described in FIG. 8represents one embodiment of step 608 described above in the discussionof FIG. 6, including additional detail. First, the process 800determines whether a plurality of cost-efficient altitudes (describedpreviously with regard to FIGS. 6 and 7) comply with an altitudeconsistency threshold (decision 802). Here, the process 800 analyzesgroups of the cost-efficient altitudes to identify areas that do notmaintain a consistent altitude value that meets the altitude consistencythreshold. The process 800 permits a transition from a first altitudevalue to a second altitude value only when the first altitude value hasbeen maintained for at least the amount of time or distance representedby the altitude consistency threshold.

When the process 800 determines that the plurality of cost-efficientaltitudes does not comply with the altitude consistency threshold (the“No” branch of 802), then the process 800 shifts one or more of thecost-efficient altitudes to comply with the altitude consistencythreshold (step 804). For example, here the process 800 identifies afirst cost-efficient altitude value that is different than a previous,second cost-efficient altitude value that is associated with an earliertime during travel of the air route, or is associated with a shorterdistance from the beginning point of the air route. In this case, theprocess 800 determines whether the cost-efficient altitude valuesmaintained the same altitude level represented by the secondcost-efficient altitude value for the minimum duration represented bythe altitude consistency threshold.

When the process 800 determines that the plurality of cost-efficientaltitudes complies with the altitude consistency threshold (the “Yes”branch of 802), then the process 800 makes no changes to the pluralityof cost-efficient altitudes and continues by identifying transitionsbetween each of the plurality of cost-efficient altitudes, wherein eachof the transitions is associated with a climb or descent (step 806).

Next, the process 800 removes a first subset of the transitionscomprising climb closely followed by descent (step 808), and thenremoves a second subset of the transitions comprising descent closelyfollowed by climb (step 810). Here, the altitude values surrounding thetransitions identified in steps 808-810 are removed from the verticaltrajectory, and the vertical trajectory is completed using the remainingaltitude values. The process 800 checks the orientation of transitionsat the following incremental distance during calculation. If theorientation of the following transition is opposite “+→−” (climbfollowed by descent) or “−→+” (descent followed by climb), then thetransition is discarded.

FIG. 9 is a flow chart that illustrates an embodiment of a process 900for calculating an optimized cost-efficient vertical trajectory on apoint-by-point basis. It should be appreciated that the process 900further describes the second technique for calculating an optimizedcost-efficient vertical trajectory, as described previously with regardto FIG. 5. First, the process 900 obtains aircraft performance data fora particular aircraft and atmospheric condition data associated with anair route (step 902). This step was described previously (see FIG. 6,step 602), and will not be redundantly described here. The process 900then identifies one of a sequence of columns associated with the airroute (step 904). The air route may include any number of columns,wherein each column is identified by an incremental distance point onthe air route (see FIG. 7, step 702), and includes the potentialaltitude values for the applicable distance point. Here, the process 900is performing an evaluation of the potential altitude values for aparticular column in the sequence, and thus identifies one column at atime.

The process 900 then calculates a cost-efficient altitude value for theone of the sequence of columns associated with the air route, based onthe aircraft performance data and the atmospheric condition data (step906). One suitable methodology for calculating the cost-efficientvertical trajectory is described previously with reference to FIG. 7. Asdescribed previously with regard to FIGS. 3-5, the process 900 computesa cost-efficient altitude value for a particular aircraft to use for aparticular air route, to reduce fuel consumption of the aircraft. Here,no constraints are taken into consideration, aside from cost-efficiency,to generate the most cost-efficient altitude value within operationallimitations of the aircraft. The process 900 evaluates the cost functionof effectively all of the feasible altitude values and selects the mostcost-efficient.

The process 900 then obtains an altitude consistency threshold (step908). The altitude consistency threshold is a time value or distancevalue for which the aircraft is configured to remain at a particularaltitude. For example, an altitude consistency threshold of one hourindicates that, for a particular air route, an aircraft remains at acurrent altitude for a minimum time period of one hour, prior to makinga transition to a different altitude. As another example, an altitudeconsistency threshold of 200 nautical miles (NM) indicates that, whiletraveling the air route, the aircraft remains at a current altitude fora minimum distance of 200 NM, prior to making a transition to adifferent altitude. In certain embodiments, the altitude consistencythreshold is a user-configurable value. In this situation, a userprovides the altitude consistency threshold via user interface. In someembodiments, however, the altitude consistency threshold may be apreconfigured value associated with a particular type of aircraft, aparticular air route, and/or particular atmospheric conditions.

Next, the process 900 adjusts the cost-efficient altitude value usingthe altitude consistency threshold, to generate an optimizedcost-efficient altitude value for the air route (step 910). One suitablemethodology for adjusting the cost-efficient vertical trajectory usingthe altitude consistency threshold is described previously withreference to FIG. 8. In step 906, the process 900 calculated acost-efficient altitude value based on the aircraft performance data andatmospheric data associated with the air route. However, the process 900does not consider the practical limitations of flight, which may includeaviation best practices and the comfort and preferences of flight crewmembers and passengers onboard the aircraft. In step 910, the process900 considers these factors by using the altitude consistency thresholdto adjust the calculated, cost-efficient altitude value into an“optimized” altitude value that considers cost-efficiency and alsomaintains each altitude level for at least the altitude consistencythreshold value.

After adjusting the cost-efficient altitude value to create an optimizedcost-efficient altitude value (step 910), the process 900 determineswhether the currently-evaluated column is the last (i.e., final) columnin the sequence of columns associated with the air route (decision 912).If the optimized cost-efficient altitude value has been calculated forthe final column in the sequence of columns for the air route (see “Yes”branch of 912), then the process 900 has completed the point-by-pointcalculation of optimized cost-efficient altitude values for the airroute, and the process 900 ends. However, if the optimizedcost-efficient altitude value has been calculated for a column otherthan the final column of the sequence of columns for the air route (the“No” branch of 912), then the process 900 returns to the beginning toidentify the next column in the sequence of columns at step 904, and toperform the calculations again. The process 900 continues in thismanner, to determine an optimized cost-efficient altitude value for eachcolumn of the air route, and ends when a complete, optimizedcost-efficient vertical trajectory for the air route has beencalculated.

Techniques and technologies may be described herein in terms offunctional and/or logical block components, and with reference tosymbolic representations of operations, processing tasks, and functionsthat may be performed by various computing components or devices. Suchoperations, tasks, and functions are sometimes referred to as beingcomputer-executed, computerized, software-implemented, orcomputer-implemented. In practice, one or more processor devices cancarry out the described operations, tasks, and functions by manipulatingelectrical signals representing data bits at memory locations in thesystem memory, as well as other processing of signals. The memorylocations where data bits are maintained are physical locations thathave particular electrical, magnetic, optical, or organic propertiescorresponding to the data bits. It should be appreciated that thevarious block components shown in the figures may be realized by anynumber of hardware, software, and/or firmware components configured toperform the specified functions. For example, an embodiment of a systemor a component may employ various integrated circuit components, e.g.,memory elements, digital signal processing elements, logic elements,look-up tables, or the like, which may carry out a variety of functionsunder the control of one or more microprocessors or other controldevices.

When implemented in software or firmware, various elements of thesystems described herein are essentially the code segments orinstructions that perform the various tasks. The program or codesegments can be stored in a processor-readable medium or transmitted bya computer data signal embodied in a carrier wave over a transmissionmedium or communication path. The “computer-readable medium”,“processor-readable medium”, or “machine-readable medium” may includeany medium that can store or transfer information. Examples of theprocessor-readable medium include an electronic circuit, a semiconductormemory device, a ROM, a flash memory, an erasable ROM (EROM), a floppydiskette, a CD-ROM, an optical disk, a hard disk, a fiber optic medium,a radio frequency (RF) link, or the like. The computer data signal mayinclude any signal that can propagate over a transmission medium such aselectronic network channels, optical fibers, air, electromagnetic paths,or RF links. The code segments may be downloaded via computer networkssuch as the Internet, an intranet, a LAN, or the like.

For the sake of brevity, conventional techniques related to signalprocessing, data transmission, signaling, network control, and otherfunctional aspects of the systems (and the individual operatingcomponents of the system) may not be described in detail herein.Furthermore, the connecting lines shown in the various figures containedherein are intended to represent exemplary functional relationshipsand/or physical couplings between the various elements. It should benoted that many alternative or additional functional relationships orphysical connections may be present in an embodiment of the subjectmatter.

Some of the functional units described in this specification have beenreferred to as “modules” in order to more particularly emphasize theirimplementation independence. For example, functionality referred toherein as a module may be implemented wholly, or partially, as ahardware circuit comprising custom VLSI circuits or gate arrays,off-the-shelf semiconductors such as logic chips, transistors, or otherdiscrete components. A module may also be implemented in programmablehardware devices such as field programmable gate arrays, programmablearray logic, programmable logic devices, or the like. Modules may alsobe implemented in software for execution by various types of processors.An identified module of executable code may, for instance, comprise oneor more physical or logical modules of computer instructions that may,for instance, be organized as an object, procedure, or function.Nevertheless, the executables of an identified module need not bephysically located together, but may comprise disparate instructionsstored in different locations that, when joined logically together,comprise the module and achieve the stated purpose for the module. Amodule of executable code may be a single instruction, or manyinstructions, and may even be distributed over several different codesegments, among different programs, and across several memory devices.Similarly, operational data may be embodied in any suitable form andorganized within any suitable type of data structure. The operationaldata may be collected as a single data set, or may be distributed overdifferent locations including over different storage devices, and mayexist, at least partially, merely as electronic signals on a system ornetwork.

While at least one exemplary embodiment has been presented in theforegoing detailed description, it should be appreciated that a vastnumber of variations exist. It should also be appreciated that theexemplary embodiment or embodiments described herein are not intended tolimit the scope, applicability, or configuration of the claimed subjectmatter in any way. Rather, the foregoing detailed description willprovide those skilled in the art with a convenient road map forimplementing the described embodiment or embodiments. It should beunderstood that various changes can be made in the function andarrangement of elements without departing from the scope defined by theclaims, which includes known equivalents and foreseeable equivalents atthe time of filing this patent application.

What is claimed is:
 1. A method for calculating vertical trajectoryvalues, the method comprising: obtaining aircraft performance data for aparticular aircraft and atmospheric condition data associated with anair route; calculating a cost-efficient vertical trajectory for the airroute, based on the aircraft performance data and the atmosphericcondition data, wherein the cost-efficient vertical trajectory comprisesa plurality of altitude values for minimizing cost for the particularaircraft during travel of the air route; obtaining an altitudeconsistency threshold comprising a time period or a distance value forwhich the particular aircraft is configured to remain at a particularaltitude; and adjusting the cost-efficient vertical trajectory using thealtitude consistency threshold, to create an optimized verticaltrajectory for the aircraft air route, by: when one or more of theplurality of altitudes altitude values do not comply with the altitudeconsistency threshold, shifting the one or more of the plurality ofaltitudes altitude values to comply with the altitude consistencythreshold; and when the plurality of altitudes altitude values do complywith the altitude consistency threshold, identifying transitions betweeneach of the plurality of altitude values; removing a first subset of thetransitions comprising climb followed by descent; and removing a secondsubset of the transitions comprising descent followed by climb.
 2. Themethod of claim 1, wherein the altitude consistency threshold comprisesa time period; and wherein adjusting the cost-efficient verticaltrajectory further comprises maintaining each of the plurality ofaltitude values for at least the time period.
 3. The method of claim 1,wherein the altitude consistency threshold comprises a time period; andwherein adjusting the cost-efficient vertical trajectory furthercomprises permitting a transition from a first one of the plurality ofaltitude values to a second one of the plurality of altitude valuesafter the first one of the plurality of altitude values has beenmaintained for at least the time period.
 4. The method of claim 1,wherein the altitude consistency threshold comprises a distance value;and wherein adjusting the cost-efficient vertical trajectory furthercomprises maintaining each of the plurality of altitude values for atleast the distance value.
 5. The method of claim 1, wherein the altitudeconsistency threshold comprises a distance value; and wherein adjustingthe cost-efficient vertical trajectory further comprises permitting atransition from a first one of the plurality of altitude values to asecond one of the plurality of altitude values after the first one ofthe plurality of altitude values has been maintained for at least thedistance value.
 6. The method of claim 1, wherein calculating acost-efficient vertical trajectory for the air route further comprises:identifying distance points throughout the air route; and calculating acost-efficient altitude for each of the distance points to generate aplurality of cost-efficient altitudes, wherein the plurality of altitudevalues comprises the plurality of cost-efficient altitudes.
 7. A systemfor calculating vertical trajectory values, the system comprising: asystem memory element; a communication device, configured to receiveatmospheric condition data associated with an air route; and at leastone processor communicatively coupled to the system memory element andthe communication device, the at least one processor configured to:calculate a cost-efficient vertical trajectory for the air route, basedon the aircraft performance data and the atmospheric condition data,wherein the cost-efficient vertical trajectory comprises a plurality ofaltitude values for minimizing cost for the particular aircraft duringtravel of the air route; and adjust the cost-efficient verticaltrajectory using an altitude consistency threshold comprising a timevalue or a distance value for which the particular aircraft isconfigured to remain at a particular altitude, to generate an optimizedvertical trajectory for the aircraft air route, by: when one or more ofthe plurality of altitudes altitude values do not comply with thealtitude consistency threshold, shifting the one or more of theplurality of altitudes altitude values to comply with the altitudeconsistency threshold; and when the plurality of altitudes altitudevalues do comply with the altitude consistency threshold, identifyingtransitions between each of the plurality of altitude values; removing afirst subset of the transitions comprising climb followed by descent;and removing a second subset of the transitions comprising descentfollowed by climb.
 8. The system of claim 7, further comprising a userinterface communicatively coupled to the at least one processor, theuser interface configured to: receive user input comprising the altitudeconsistency threshold; and transmit the altitude consistency thresholdto the at least one processor.
 9. The system of claim 7, wherein the atleast one processor is further configured to communicate with the systemmemory element to obtain the altitude consistency threshold.
 10. Thesystem of claim 7, wherein the altitude consistency threshold comprisesa time period; and wherein adjusting the cost-efficient verticaltrajectory further comprises maintaining each of the plurality ofaltitude values for at least the time period.
 11. The system of claim 7,wherein the altitude consistency threshold comprises a distance value;and wherein adjusting the cost-efficient vertical trajectory furthercomprises maintaining each of the plurality of altitude values for atleast the distance value.
 12. The system of claim 7, wherein the atleast one processor is further configured to: identify distance pointsthroughout the air route; and calculate a cost-efficient altitude foreach distance point to generate a plurality of cost-efficient altitudes,wherein the plurality of altitude values comprises the plurality ofcost-efficient altitudes.
 13. A non-transitory, computer-readable mediumcontaining instructions thereon, which, when executed by a processor,perform a method comprising: identifying distance points throughout anair route; calculating a cost-efficient altitude for each of thedistance points to determine a plurality of cost-efficient altitudes,wherein the plurality of cost-efficient altitudes is applicable to aparticular aircraft traveling the air route; determining whether each ofthe plurality of cost-efficient altitudes complies with an altitudeconsistency threshold comprising a time value or a distance value forwhich the particular aircraft is configured to remain at a particularaltitude; and creating an optimized vertical trajectory, by: when one ormore of the plurality of cost-efficient altitudes does not comply withthe altitude consistency threshold, shifting the one or more of theplurality of cost-efficient altitudes to comply with the altitudeconsistency threshold; and when the plurality of cost-efficientaltitudes do comply with the altitude consistency threshold, identifyingtransitions between each of the plurality of altitude valuescost-efficient altitudes; removing a first subset of the transitionscomprising climb followed by descent; and removing a second subset ofthe transitions comprising descent followed by climb.
 14. Thenon-transitory, computer-readable medium of claim 13, wherein thealtitude consistency threshold comprises a time period; and whereinshifting the one of the plurality of cost-efficient altitudes furthercomprises maintaining a value for each of the plurality ofcost-efficient altitudes for at least the time period.
 15. Thenon-transitory, computer-readable medium of claim 13, wherein thealtitude consistency threshold comprises a distance value; and whereinshifting the one of the plurality of cost-efficient altitudes furthercomprises maintaining a value for each of the plurality ofcost-efficient altitudes for at least the distance value.